What is the metal catalyst used in catalytic reduction of alkene to change into alkane?
Platinum, palladium, rhodium...?
For catalytic hydrogenation....
The metal surface is some finely divided, often PRECIOUS metal, i.e. of rhodium, platinum, iridium...or something. Now these catalysts are EXPENSIVE (rhodium and iridium are phenomenally expensive), but metals are so active that the catalyst loading can be extremely small, and sometimes recovery of catalyst from the product is not even attempted.